Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Triangulum Pinwheel: 02-16 (55), 02-17 (50), 02-18 (46), 02-19 (39), 02-20 (32) — by astronomy; check the weather when the night is within four days.

2037-02-16astronomy score per night — click a bar for that night2037-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-02-16 Mon	55	—	unknown	19:30–21:40 (good, 2.17 h)	79.2° 16:10	10.19	3%	50.5°
2037-02-17 Tue	50	—	unknown	19:35–21:40 (good, 2.08 h)	79.2° 16:05	10.15	7%	40.9°
2037-02-18 Wed	46	—	unknown	19:35–21:35 (good, 2.0 h)	79.2° 16:00	10.11	12%	32.5°
2037-02-19 Thu	39	—	unknown	19:35–21:20 (good, 1.75 h)	79.1° 16:00	10.07	19%	26.4°
2037-02-20 Fri	32	—	unknown	19:35–21:10 (good, 1.58 h)	79.2° 15:55	10.03	27%	24.7°
2037-02-21 Sat	25	—	unknown	19:35–21:00 (good, 1.42 h)	79.2° 15:50	9.98	36%	28.4°
2037-02-22 Sun	20	—	unknown	19:40–19:45 (good, 0.08 h)	79.2° 15:45	9.94	46%	36.2°
2037-02-23 Mon	16	—	unknown	19:40–21:35 (marginal, 1.92 h)	79.2° 15:40	9.9	57%	46.2°
2037-02-24 Tue	14	—	unknown	19:40–21:25 (marginal, 1.75 h)	79.1° 15:40	9.86	68%	57.7°
2037-02-25 Wed	14	—	unknown	19:40–21:25 (marginal, 1.75 h)	79.2° 15:35	9.81	78%	70.0°
2037-02-26 Thu	15	—	unknown	19:45–21:20 (marginal, 1.58 h)	79.2° 15:30	9.77	86%	83.0°
2037-02-27 Fri	17	—	unknown	19:45–20:10 (good, 0.42 h)	79.2° 15:25	9.72	94%	96.5°
2037-02-28 Sat	21	—	unknown	19:45–20:35 (good, 0.83 h)	79.1° 15:20	9.68	98%	110.2°
2037-03-01 Sun	23	—	unknown	19:45–20:40 (good, 0.92 h)	79.2° 15:20	9.63	100%	123.7°
2037-03-02 Mon	22	—	unknown	19:50–20:35 (good, 0.75 h)	79.2° 15:15	9.59	99%	136.5°
2037-03-03 Tue	24	—	unknown	19:50–20:35 (good, 0.75 h)	79.2° 15:10	9.54	94%	147.4°
2037-03-04 Wed	24	—	unknown	19:50–20:40 (good, 0.83 h)	79.2° 15:05	9.49	88%	154.4°
2037-03-05 Thu	22	—	unknown	19:50–20:35 (good, 0.75 h)	79.1° 15:05	9.45	79%	154.5°
2037-03-06 Fri	21	—	unknown	19:50–20:30 (good, 0.67 h)	79.2° 15:00	9.4	69%	148.3°
2037-03-07 Sat	18	—	unknown	19:55–20:25 (good, 0.5 h)	79.2° 14:55	9.35	59%	138.9°
2037-03-08 Sun	17	—	unknown	19:55–20:25 (good, 0.5 h)	79.2° 14:50	9.3	49%	128.3°
2037-03-09 Mon	15	—	unknown	19:55–20:20 (good, 0.42 h)	79.2° 14:45	9.26	39%	117.4°
2037-03-10 Tue	14	—	unknown	19:55–20:15 (good, 0.33 h)	79.1° 14:45	9.21	29%	106.5°
2037-03-11 Wed	11	—	unknown	20:00–20:10 (good, 0.17 h)	79.2° 14:40	9.16	21%	95.5°
2037-03-12 Thu	9	—	unknown	20:00–20:05 (good, 0.08 h)	79.2° 14:35	9.11	14%	84.7°
2037-03-13 Fri	8	—	unknown	20:00–20:05 (good, 0.08 h)	79.2° 14:30	9.06	8%	74.0°
2037-03-14 Sat	7	—	unknown	19:30–20:30 (marginal, 1.0 h)	79.1° 14:25	9.01	4%	63.4°
2037-03-15 Sun	5	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:25	8.96	1%	53.1°
2037-03-16 Mon	4	—	unknown	20:05–20:20 (marginal, 0.25 h)	79.2° 14:20	8.91	0%	43.3°
2037-03-17 Tue	3	—	unknown	19:35–19:50 (marginal, 0.25 h)	79.2° 14:15	8.86	1%	34.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-02-16&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.